What’s the Difference Between Low and High Voltage?

on November 6, 2015

Whether you’ve seen it on fixtures, wires, or electrical
panels, you’ve probably run across low and high voltage warnings. What’s the difference and how do you know
which is better for use? The answers are
actually rather simple.

Official Difference

The difference in electrical potential between source and
sink, or voltage as it’s more commonly known, is just one of the many
measurements we use to rate devices and power lines. High voltage is usually considered to be
anything that has the potential to cause harm or injury directly. The IEC ratings for voltage list high voltage
devices and lines as anything over 1,000 volts for AC circuits and 1,500 volts
for DC circuits while low voltage circuits are between 50 and 1,000 VAC or
120-1500 VDC.

However, this places all home electrical wiring in the low
voltage class (or lower). Housing
voltage (also known as main or line voltage) is typically between 100 and 250
VAC. For home owners, this is considered
high voltage. With this consideration
for the general homeowner, standard 5- to 24-volt devices are low voltage
instruments. With more and more simple
USB devices becoming the norm, the 5-volt USB outlet (and low voltage adapters
in general) are becoming more common.

Use Cases

So how and where are these different voltages used? Most homes are wired on the 100-240 VAC
standard. Light sockets don’t convert
the energy, they simply deliver roughly 120 VAC to the bulb placed in the
socket. Most devices operate off this
standard, even if they don’t use 120 AC electricity. LED light bulbs, CFLs, fans, even your
computer plugs into at 120 volt outlet.
Almost all of the electrical wiring in your home is going to be line or high voltage. This is
because it’s easier to transmit at that voltage and it makes more sense for
your device to convert the source voltage into an accepted standard than to try
and make all devices conform to the standard of your home.

While high voltage circuits are standard, low voltage
circuits and devices are specialized for tasks.
Electrical fixtures in yards or landscapes are a prime candidate for low
voltages. Using a lower voltage system
promotes safety for homeowners during yardwork after weather. The drawback to using a low voltage system is
that it cannot run as far as a higher voltage circuit. Large yards would need high voltage cables,
which requires deep excavation and clear marking or recorded blueprints to
prevent future mishaps while digging.

Smart systems and custom energy-efficient lighting are great
candidates for low voltage wiring. LED
lights that aren’t designed to fit in a standard socket operate off of low
voltage DC lines. Installing a low
voltage line for these lights means fewer conversions within your home. Likewise, creating a smart home uses multiple
digital devices. Installing low voltage
circuits to meet these demands may not be a bad idea depending on how many
circuits you need.

Not sure whether you’re working on low or high voltage? Call Mainstream Electric. We’ll take a look at your voltage and we’ll even help you on your current project if you’d like!